Ubuntu升级到18.04后无法启动Xorg

将Ubuntu升级到18.04（从17.10开始）后，Xorg无法启动。 它只是在黑色和灰色空白屏幕之间反复切换。 我重新配置grub以使用nomodeset以文本模式启动。 startx命令无法启动Xorg服务器。 我有一个内置的英特尔显卡。 这是/var/log/Xorg.0.log的输出：

[ 38.698] (II) config/udev: Adding input device HDA Intel PCH HDMI/DP,pcm=3 (/dev/input/event10) [ 38.698] (II) No input driver specified, ignoring this device. [ 38.698] (II) This device may have been added with another device file. [ 38.698] (II) config/udev: Adding input device HDA Intel PCH HDMI/DP,pcm=7 (/dev/input/event11) [ 38.698] (II) No input driver specified, ignoring this device. [ 38.699] (II) This device may have been added with another device file. [ 38.699] (II) config/udev: Adding input device HDA Intel PCH Rear Mic (/dev/input/event5) [ 38.699] (II) No input driver specified, ignoring this device. [ 38.699] (II) This device may have been added with another device file. [ 38.699] (II) config/udev: Adding input device HDA Intel PCH Front Mic (/dev/input/event6) [ 38.699] (II) No input driver specified, ignoring this device. [ 38.699] (II) This device may have been added with another device file. [ 38.699] (II) config/udev: Adding input device HDA Intel PCH Line (/dev/input/event7) [ 38.699] (II) No input driver specified, ignoring this device. [ 38.699] (II) This device may have been added with another device file. [ 38.700] (II) config/udev: Adding input device HDA Intel PCH Line Out (/dev/input/event8) [ 38.700] (II) No input driver specified, ignoring this device. [ 38.700] (II) This device may have been added with another device file. [ 38.700] (II) config/udev: Adding input device HDA Intel PCH Front Headphone (/dev/input/event9) [ 38.700] (II) No input driver specified, ignoring this device. [ 38.700] (II) This device may have been added with another device file. [ 41.427] (**) Option "fd" "21" [ 41.427] (II) event1 - Power Button: device removed [ 41.427] (**) Option "fd" "24" [ 41.427] (II) event0 - Power Button: device removed [ 41.427] (**) Option "fd" "25" [ 41.427] (II) event2 - PixArt USB Optical Mouse: device removed [ 41.427] (**) Option "fd" "26" [ 41.427] (II) event3 - USB Keyboard: device removed [ 41.427] (**) Option "fd" "27" [ 41.427] (II) event4 - USB Keyboard: device removed [ 41.428] (II) UnloadModule: "libinput" [ 41.428] (II) systemd-logind: releasing fd for 13:68 [ 41.444] (II) UnloadModule: "libinput" [ 41.444] (II) systemd-logind: releasing fd for 13:67 [ 41.460] (II) UnloadModule: "libinput" [ 41.460] (II) systemd-logind: releasing fd for 13:66 [ 41.512] (II) UnloadModule: "libinput" [ 41.512] (II) systemd-logind: releasing fd for 13:64 [ 41.528] (II) UnloadModule: "libinput" [ 41.528] (II) systemd-logind: releasing fd for 13:65 [ 41.653] (II) Server terminated successfully (0). Closing log file. 

grep“（EE）”/ var / log / Xorg.0.log的输出：

 [ 86.288] (EE) open /dev/dri/card0: No such file or directory [ 86.289] (EE) open /dev/dri/card0: No such file or directory [ 86.289] (EE) Screen 0 deleted because of no matching config section. [ 86.294] (EE) AIGLX: reverting to software rendering